Generations of Americans are leaving movie theaters this week having learned and even felt, perhaps for the first time, the pain and shame of an era many never really knew before.

Now they know: Before America was a nation of desegregated schools, buses and restaurants — before most Americans had even heard of Martin Luther Ling Jr. — our country’s civil rights generation had but one icon of human equality. He stood head and shoulders above all others — even when he was sliding in the dirt and jabbing his toe beneath Yogi Berra’s mitt, famously stealing home in the World Series.

This powerful movie celebrates how, in 1947, the man with the blue 42 on his Brooklyn Dodgers uniform became the first black athlete to play major league baseball. “42” doesn’t merely show us the bigotry and death threats Robinson endured. It educates us by allowing us to feel his pain. And our shame.

Yet “42” is really just the end of the beginning of the Jackie Robinson story. It stops after that epic first year. But the real Jackie Robinson story — his story and our nation’s story — went on for a quarter century.

So today we’ll educate ourselves by taking a guided tour of Washington’s monument to Jackie Robinson. You never heard of it? Probably not. After all, it doesn’t tower above the capital skyline like George Washington’s, nor sit and gaze down at us like Abe Lincoln’s.

Chris Pizzello, Invision/AP

Rachel Robinson, second from right, widow of the late baseball legend Jackie Robinson, at the Los Angeles premiere of "42."

Washington’s monument to Jackie Robinson stands just 131 pages tall, a monument originally made of paper and microfilm. It is the FBI’s file on Jack Roosevelt Robinson. Part of it is the FBI’s investigation of all those evil death threats. The rest mainly feeds FBI Director J. Edgar Hoover’s conviction that America’s civil rights movement was but a tool of Soviet Communism’s plan to subvert American democracy.

Here — read the FBI’s words for yourself. The FBI memos, originally stamped “CONFIDENTIAL” or “SECRET,” were declassified in 1984.

The FBI files reach back to when Robinson signed his first Dodgers minor league contract:

“The June 1, 1946, issue of ‘People’s Voice’ contained an article and photograph of Jackie Robinson, reflecting that Jackie Robinson, the first negro (sic) to break into organized baseball, had accepted chairmanship of the New York State organizing committee for United Negro and Allied Veterans of America (UNAVA). ... The ‘People’s Voice’ has been cited by the California Committee on Un-American Activities report, 1948, as among publications which the committee found ‘to be Communist initiated and controlled... so strongly influenced as to be in the Stalin solar system.’

“... The UNAVA has been cited as a communist front ‘to provoke racial friction’ by the Internal Security Subcommittee of the Senate Judiciary Committee in its Handbook for Americans. ...”

By 1952, Robinson was a Dodger all-star and the FBI discovered he dared to be in favor of ending racial discrimination in a famous Long Island suburban community:

“CONFIDENTIAL ... On February 15, 1952, a second source who has furnished reliable information in the past stated that the Committee to End Discrimination in Levittown, New York, announced that Jackie Robinson, famous Dodger baseball star, told the committee he would cooperate with them to end discrimination in Levittown. ...”

Hoover’s acolytes had a fondness for feeding the boss what he liked — especially in provocative subject lines.

“SUBJECT: Communist Infiltration of the National Association for the Advancement of Colored People.” The special agent in charge of the FBI’s New Haven office was writing Hoover on Oct. 16, 1963, to report an intelligence coup. “Enclosed for the Bureau are three copies of a letterhead memorandum pertaining to Jackie Robinson,” his memo began. The FBI’s purloined NAACP document trove revealed Robinson was serving on the NAACP’s board of directors and its National Life Membership Committee.

The FBI files also contained this intelligence from the anti-communist sleuths of the House Un-American Activities Committee. They had come up with something in their search for communist links with Jack Roosevelt Robinson — but neither the committee nor the FBI checked further before writing this:

“ ‘Soviet Russia Today,’ for December 1938, page 29, reflected that one J. R. Robinson of N.Y.C. was a contributor.” Time out! Baseball’s future star, Jackie Robinson, was then a 19-year-old student at Pasadena Junior College, now Pasadena City College, in California.

To read the FBI files on Robinson today is to come away shaking our heads at how we could ever have let things get so out of control in that era of anti-commie witch-hunts.

What the FBI files purport to report in the rest of the Jackie Robinson story was so tame, so lame, that their sum total is, yet again, our shame.